Incorporation of surfactin-containing Bacillus subtilis fermentation broth in fresh noodles: shelf life extension and property enhancement

To elucidate the mechanisms by which surfactin-containing Bacillus subtilis fermentation broth (SFB) prolongs the shelf life of fresh noodles (FNs), this study evaluated its effects on microbial quality, rheological behavior, cooking and textural properties, and water distribution of FNs during storage at 15 °C. The results demonstrated SFB exhibited dose-dependent antibacterial activity, extending the shelf life of FNs from 3 days (control) to 9–19 days at concentrations of 90–360 g/kg. SFB supplementation mitigated water migration, reduced cooking loss, and stabilized textural properties by promoting starch-protein cross-linking and gluten network formation. Rheological analysis revealed improved elastic (G′) and viscous (G″) moduli in SFB-treated FNs, indicating improved viscoelasticity and gluten strength, which contributed to a firmer, chewier texture. Additionally, SFB improved the thermal stability and structural integrity of starch. These effects might be attributed to the emulsifying activity of surfactin and its synergistic interactions with polysaccharides and amino acids via hydrophilic and hydrophobic group interactions. This work provides a practical strategy for utilizing fermentation broth directly as a natural preservative, offering economic and consumer-friendly advantages for the food industry. Future work should focus on optimizing SFB concentration for sensory acceptability and validating its preservative efficacy under varied storage conditions to enhance its commercial applicability.